DESCRIPTION: Fix performance issue when using "\d tablename" on a server
with many tables
We introduce a filter to every query on pg_class to automatically remove
shards. This is useful to make sure \d and PgAdmin are not cluttered
with shards. However, the way we were introducing this filter was using
`securityQuals` which can have negative impact on query performance.
On clusters with 100k+ tables this could cause a simple "\d tablename"
command to take multiple seconds, because a skipped optimization by
Postgres causes a full table scan. This changes the code to introduce
this filter in the regular `quals` list instead of in `securityQuals`.
Which causes Postgres to use the intended optimization again.
For reference, this was initially reported as a Postgres issue by me:
https://www.postgresql.org/message-id/flat/4189982.1712785863%40sss.pgh.pa.us#b87421293b362d581ea8677e3bfea920
DESCRIPTION: Fix PG upgrades when invalid rebalance strategies exist
Without this change an upgrade of a cluster with an invalid rebalance
strategy would fail with an error like this:
```
cache lookup failed for shard_cost_function with oid 6077337
CONTEXT: SQL statement "SELECT citus_validate_rebalance_strategy_functions(
NEW.shard_cost_function,
NEW.node_capacity_function,
NEW.shard_allowed_on_node_function)"
PL/pgSQL function citus_internal.pg_dist_rebalance_strategy_trigger_func() line 5 at PERFORM
SQL statement "INSERT INTO pg_catalog.pg_dist_rebalance_strategy SELECT
name,
default_strategy,
shard_cost_function::regprocedure::regproc,
node_capacity_function::regprocedure::regproc,
shard_allowed_on_node_function::regprocedure::regproc,
default_threshold,
minimum_threshold,
improvement_threshold
FROM public.pg_dist_rebalance_strategy"
PL/pgSQL function citus_finish_pg_upgrade() line 115 at SQL statement
```
This fixes that by disabling the trigger and simply re-inserting the
invalid rebalance strategy without checking. We could also silently
remove it, but this seems nicer.
And when that is the case, directly use it as "host" parameter for the
connections between nodes and use the "hostname" provided in
pg_dist_node / pg_dist_poolinfo as "hostaddr" to avoid host name lookup.
This is to avoid allowing dns resolution (and / or setting up DNS names
for each host in the cluster). This already works currently when using
IPs in the hostname. The only use of setting host is that you can then
use sslmode=verify-full and it will validate that the hostname matches
the certificate provided by the node you're connecting too.
It would be more flexible to make this a per-node setting, but that
requires SQL changes. And we'd like to backport this change, and
backporting such a sql change would be quite hard while backporting this
change would be very easy. And in many setups, a different hostname for
TLS validation is actually not needed. The reason for that is
query-from-any node: With query-from-any-node all nodes usually have a
certificate that is valid for the same "cluster hostname", either using
a wildcard cert or a Subject Alternative Name (SAN). Because if you load
balance across nodes you don't know which node you're connecting to, but
you still want TLS validation to do it's job. So with this change you
can use this same "cluster hostname" for TLS validation within the
cluster. Obviously this means you don't validate that you're connecting
to a particular node, just that you're connecting to one of the nodes in
the cluster, but that should be fine from a security perspective (in
most cases).
Note to self: This change requires updating
https://docs.citusdata.com/en/latest/develop/api_guc.html#citus-node-conninfo-text.
DESCRIPTION: Allows overwriting host name for all inter-node connections
by supporting "host" parameter in citus.node_conninfo
DESCRIPTION: Fixes a crash caused by some form of ALTER TABLE ADD COLUMN
statements. When adding multiple columns, if one of the ADD COLUMN
statements contains a FOREIGN constraint ommitting the referenced
columns in the statement, a SEGFAULT occurs.
For instance, the following statement results in a crash:
```
ALTER TABLE lt ADD COLUMN new_col1 bool,
ADD COLUMN new_col2 int references rt;
```
Fixes#7520.
This PR changes the order in which the locks are acquired (for the
target and reference tables), when a modify request is initiated from a
worker node that is not the "FirstWorkerNode".
To prevent concurrent writes, locks are acquired on the first worker
node for the replicated tables. When the update statement originates
from the first worker node, it acquires the lock on the reference
table(s) first, followed by the target table(s). However, if the update
statement is initiated in another worker node, the lock requests are
sent to the first worker in a different order. This PR unifies the
modification order on the first worker node. With the third commit,
independent of the node that received the request, the locks are
acquired for the modified table and then the reference tables on the
first node.
The first commit shows a sample output for the test prior to the fix.
Fixes#7477
---------
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
When using a CASE WHEN expression in the body
of the function that is used in the DO block, a segmentation
fault occured. This fixes that.
Fixes#7381
---------
Co-authored-by: Konstantin Morozov <vzbdryn@yahoo.com>
DESCRIPTION: Adds support for distributed `ALTER/DROP ROLE` commands
from the databases where Citus is not installed
---------
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
In preprocess phase, we save the original database name, replace
dbname field of CreatedbStmt with a temporary name (to let Postgres
to create the database with the temporary name locally) and then
we insert a cleanup record for the temporary database name on all
nodes **(\*\*)**.
And in postprocess phase, we first rename the temporary database
back to its original name for local node and then return a list of
distributed DDL jobs i) to create the database with the temporary
name and then ii) to rename it back to its original name on other
nodes. That way, if CREATE DATABASE fails on any of the nodes, the
temporary database will be cleaned up by the cleanup records that
we inserted in preprocess phase and in case of a failure, we won't
leak any databases called as the name that user intended to use for
the database.
Solves the problem documented in
https://github.com/citusdata/citus/issues/7369
for CREATE DATABASE commands.
**(\*\*):** To ensure that we insert cleanup records on all nodes,
with this PR we also start requiring having the coordinator in the
metadata because otherwise we would skip inserting a cleanup record
for the coordinator.
When adding CREATE/DROP DATABASE propagation in #7240, luckily
we've added EnsureSupportedCreateDatabaseCommand() check into
deparser too just to be on the safe side. That way, today CREATE
DATABASE commands from non-main dbs don't silently allow unsupported
options.
I wasn't aware of this when merging #7439 and hence wanted to add
a test so that we don't mistakenly remove that check from deparser
in future.
Fix for the #7519
In metadata sync phase, grant statements for roles are being fetched and
propagated from catalog tables.
However, in some cases grant .. with admin option clauses executes after
the granted by statements which causes #7519 error.
We will fix this issue with the grantor propagation task in the project
DESCRIPTION: Adds support for distributed `CREATE/DROP DATABASE `
commands from the databases where Citus is not installed
---------
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
DESCRIPTION: Adds support for distributed `GRANT .. ON DATABASE TO USER`
commands from the databases where Citus is not installed
---------
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
DESCRIPTION: Adds support for distributed role-membership management
commands from the databases where Citus is not installed (`GRANT <role>
TO <role>`)
This PR also refactors the code-path that allows executing some of the
node-wide commands so that we use send deparsed query string to other
nodes instead of the `queryString` passed into utility hook.
---------
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
DESCRIPTION: Fixes incorrect propagating of `GRANTED BY` and
`CASCADE/RESTRICT` clauses for `REVOKE` statements
There are two issues fixed in this PR
1. granted by statement will appear for revoke statements as well
2. revoke/cascade statement will appear after granted by
Since granted by statements does not appear in statements, this bug
hasn't been visible until now. However, after activating the granted by
statement for revoke, order problem arised and this issue was fixed
order problem for cascade/revoke as well
In summary, this PR provides usage of granted by statements properly now
with the correct order of statements.
We can verify the both errors, fixed with just single statement
REVOKE dist_role_3 from non_dist_role_3 granted by test_admin_role
cascade;
DESCRIPTION: Resolves an issue that disrupts distributed GRANT
statements with the grantor option
In this issue 3 issues are being solved:
1.Correcting the erroneous appending of multiple granted by in the
deparser.
2Adding support for grantor (granted by) in grant role propagation.
3. Implementing grantor (granted by) support during the metadata sync
grant role propagation phase.
Limitations: Currently, the grantor must be created prior to the
metadata sync phase. During metadata sync, both the creation of the
grantor and the grants given by that role cannot be performed, as the
grantor role is not detected during the dependency resolution phase.
---------
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
Moves the following functions to the Citus internal schema:
citus_internal_local_blocked_processes
citus_internal_global_blocked_processes
citus_internal_mark_node_not_synced
citus_internal_unregister_tenant_schema_globally
citus_internal_update_none_dist_table_metadata
citus_internal_update_placement_metadata
citus_internal_update_relation_colocation
citus_internal_start_replication_origin_tracking
citus_internal_stop_replication_origin_tracking
citus_internal_is_replication_origin_tracking_active
#7405
---------
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
DESCRIPTION: citus_move_shard_placement now fails early when shard
cannot be safely moved
The implementation is quite simplistic -
`citus_move_shard_placement(...)` will fail with an error if there's any
new node in the cluster that doesn't have reference tables yet.
It could have been finer-grained, i.e. erroring only when trying to move
a shard to an unitialized node. Looking at the related functions -
`replicate_reference_tables()` or `citus_rebalance_start()`, I think
it's acceptable behaviour. These other functions also treat "any"
unitialized node as a temporary anomaly.
Fixes#7426
---------
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
Moves the following functions:
citus_internal_delete_colocation_metadata
citus_internal_delete_partition_metadata
citus_internal_delete_placement_metadata
citus_internal_delete_shard_metadata
citus_internal_delete_tenant_schema
Move more functions to citus_internal schema, the list:
citus_internal_add_placement_metadata
citus_internal_add_shard_metadata
citus_internal_add_tenant_schema
citus_internal_adjust_local_clock_to_remote
citus_internal_database_command
#7405
Move citus_internal_acquire_citus_advisory_object_class_lock and
citus_internal_add_colocation_metadata functions from pg_catalog to
citus_internal.
#7405
Fixes a bug that breaks queries from non-maindbs when
citus.local_hostname is set to a value different than "localhost".
This is a very old bug doesn't cause a problem as long as Citus catalog
is available to FindWorkerNode(). And the catalog is always available
unless we're in non-main database, which might be the case on main but
not on older releases, hence not adding a `DESCRIPTION`. For this
reason, I don't see a reason to backport this.
Maybe we should totally refrain using LOCAL_HOST_NAME in all code-paths,
but not doing that in this PR as the other paths don't seem to be
breaking something that is user-facing.
```c
char *
GetAuthinfo(char *hostname, int32 port, char *user)
{
char *authinfo = NULL;
bool isLoopback = (strncmp(LOCAL_HOST_NAME, hostname, MAX_NODE_LENGTH) == 0 &&
PostPortNumber == port);
if (IsTransactionState())
{
int64 nodeId = WILDCARD_NODE_ID;
/* -1 is a special value for loopback connections (task tracker) */
if (isLoopback)
{
nodeId = LOCALHOST_NODE_ID;
}
else
{
WorkerNode *worker = FindWorkerNode(hostname, port);
if (worker != NULL)
{
nodeId = worker->nodeId;
}
}
authinfo = GetAuthinfoViaCatalog(user, nodeId);
}
return (authinfo != NULL) ? authinfo : "";
}
```
This patch includes the username in the reported error message.
This makes debugging easier when certain commands open connections
as other users than the user that is executing the command.
```
monitora_snapshot=# SELECT citus_move_shard_placement(102030, 'monitora.db-dev-worker-a', 6005, 'monitora.db-dev-worker-a', 6017);
ERROR: connection to the remote node monitora_user@monitora.db-dev-worker-a:6017 failed with the following error: fe_sendauth: no password supplied
Time: 40,198 ms
```
This PR makes the connections to other nodes for
`mark_object_distributed` use the same user as
`execute_command_on_remote_nodes_as_user` so they'll use the same
connection.
DESCRIPTION: Adds comment on database and role propagation.
Example commands are as below
comment on database <db_name> is '<comment_text>'
comment on database <db_name> is NULL
comment on role <role_name> is '<comment_text>'
comment on role <role_name> is NULL
---------
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
Adding upgrade_basic_before_non_mixed.sql file because while
upgrade_basic_after_non_mixed exist, its before variation didn't exist
as we don't have any "before" steps. However, run_test.py assumes that
all "after" files do have a "before" variation as well. So this PR adds
an empty upgrade_basic_before_non_mixed.sql file.
Also, given that we don't have such a version called as 12.1devel
anymore, change it to 12.1.1.
And finally, let CI skip testing flakyness for upgrade tests both
because it's quite hard to get flaky-test-detection job working for
upgrade tests and also because in the end it is not much useful to test
upgrade tests against flakyness.
DESCRIPTION: Adds support for issuing `CREATE`/`DROP` DATABASE commands
from worker nodes
With this commit, we allow issuing CREATE / DROP DATABASE commands from
worker nodes too.
As in #7278, this is not allowed when the coordinator is not added to
metadata because we don't ever sync metadata changes to coordinator
when adding coordinator to the metadata via
`SELECT citus_set_coordinator_host('<hostname>')`, or equivalently, via
`SELECT citus_add_node(<coordinator_node_name>, <coordinator_node_port>, 0)`.
We serialize database management commands by acquiring a Citus specific
advisory lock on the first primary worker node if there are any workers in the
cluster. As opposed to what we've done in https://github.com/citusdata/citus/pull/7278
for role management commands, we try to avoid from running into distributed deadlocks
as much as possible. This is because, while distributed deadlocks that can happen around
role management commands can be detected by Citus, this is not the case for database
management commands because most of them cannot be run inside in a transaction block.
In that case, Citus cannot even detect the distributed deadlock because the command is not
part of a distributed transaction at all, then the command execution might not return the
control back to the user for an indefinite amount of time.
This fixes#7230.
First of all, using HeapTupleHeaderGetDatumLength(heapTuple) is
definetly wrong, it gives a number that's 4 times less than the correct
tuple size (heapTuple.t_len). See
https://github.com/postgres/postgres/blob/REL_16_0/src/include/access/htup_details.h#L455-L456https://github.com/postgres/postgres/blob/REL_16_0/src/include/varatt.h#L279https://github.com/postgres/postgres/blob/REL_16_0/src/include/varatt.h#L225-L226
When I fixed it, the limit_intermediate_size test failed, so I tried to
understand what's going on there. In original commit fd546cf these
queries were supposed to fail. Then in b3af63c three of the queries that
were supposed to fail suddenly worked and tests were changed to pass
without understanding why the output had changed or how to keep test
testing what it had to test. Even comments saying that these queries
should fail were left untouched. Commit message gives no clue about why
exactly test has changed:
> It seems that when we use adaptive executor instead of task tracker,
we
> exceed the intermediate result size less in the test. Therefore
updated
> the tests accordingly.
Then 3fda2c3 also blindly raised the limit for one of the queries to
keep it working:
3fda2c3254 (diff-a9b7b617f9dfd345318cb8987d5897143ca1b723c87b81049bbadd94dcc86570R19)
When in fe3caf3 that HeapTupleHeaderGetDatumLength(heapTuple) call was
finally added, one of those test queries became failing again.
The other two of them now also failing after the fix. I don't understand
how exactly the calculation of "intermediate result size" that is
limited by citus.max_intermediate_result_size had changed through
b3af63c and fe3caf3, but these numbers are now closer to what
they originally were when this limitation was added in
fd546cf. So these queries should fail, like in the original
version of the limit_intermediate_size test.
Co-authored-by: Karina Litskevich <litskevichkarina@gmail.com>
foreign_key_to_reference_shard_rebalance failed because partition of
2024 year does not exist, fixed by add default partition.
Replaces https://github.com/citusdata/citus/pull/7396 by adding a rule
that allows properly testing foreign_key_to_reference_shard_rebalance
via run_test.py.
Closes#7396
Co-authored-by: chuhx <148182736+cstarc1@users.noreply.github.com>
DESCRIPTION: Adds REASSIGN OWNED BY propagation
This pull request introduces the propagation of the "Reassign owned by"
statement. It accommodates both local and distributed roles for both the
old and new assignments. However, when the old role is a local role, it
undergoes filtering and is not propagated. On the other hand, if the new
role is a local role, the process involves first creating the role on
worker nodes before propagating the "Reassign owned" statement.
DESCRIPTION: Adds database connection limit, rename and set tablespace
propagation
In this PR, below statement propagations are added
alter database <database_name> with allow_connections = <boolean_value>;
alter database <database_name> rename to <database_name2>;
alter database <database_name> set TABLESPACE <table_space_name>
---------
Co-authored-by: Jelte Fennema-Nio <github-tech@jeltef.nl>
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
DESCRIPTION: Adds support for 2PC from non-Citus main databases
This PR only adds support for `CREATE USER` queries, other queries need
to be added. But it should be simple because this PR creates the
underlying structure.
Citus main database is the database where the Citus extension is
created. A non-main database is all the other databases that are in the
same node with a Citus main database.
When a `CREATE USER` query is run on a non-main database we:
1. Run `start_management_transaction` on the main database. This
function saves the outer transaction's xid (the non-main database
query's transaction id) and marks the current query as main db command.
2. Run `execute_command_on_remote_nodes_as_user("CREATE USER
<username>", <username to run the command>)` on the main database. This
function creates the users in the rest of the cluster by running the
query on the other nodes. The user on the current node is created by the
query on the outer, non-main db, query to make sure consequent commands
in the same transaction can see this user.
3. Run `mark_object_distributed` on the main database. This function
adds the user to `pg_dist_object` in all of the nodes, including the
current one.
This PR also implements transaction recovery for the queries from
non-main databases.
Ivan Vyazmitinov
Jelte Fennema-Nio
Onur Tirtir
Emel Şimşek
eaydingol
copetol
Gürkan İndibay
Halil Ozan Akgül
Filip Sedlák
Filip Sedlák
Teja Mupparti
Karina